Fork-lift finger construction



Nov. 21, 1967 w. E. MARTIN ET 3,353,697

FORK-LIFT FINGER CONSTRUCTION 2 Sheets-Sheet 1 Filed Juhe 25, 1965 IgJ.

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Nbv. 21, 1-967 w. E. MARTIN ET AL 3,353,697

FORK-LIFT FINGER CONSTRUCTION 2 Sheets-Sheet 2 Filed June 25, 1965INIVENTORS. Will/3 E. Mczr'r/n Paul H. Johnson F/oyd L. Reaser' gag ATTORNf YS.

United States Patent 3,353,697 FORK-LIFT FINGER CONSTRUCTION Willis E.Martin, Tecumseh, and Paul H. Johnson and Floyd L. Reaser, Topeka,Kans., assignors to The Fleming Co., Incorporated, Topeka, Kans., acorporation of Kansas Filed June 25, 1965, Ser. No. 466,971 2 Claims.(Cl. 214-4520) ABSTRACT OF THE DISCLOSURE An extension for a fork-lifttruck finger having a rounded, convex outermost edge and a loop memberformed at the rear of the extension and adapted to receive the lifttruck finger therethrough. A plurality of parallel, upwardly taperingflanges on the bottom surface of the extension cooperate with the lifttruck finger to releasably support the extension on the finger.

This invention relates to hoisting apparatus, and more particularly, toa novel, removable extension for the fingers of lift trucks and thelike.

It has come to be a general practice in large warehousing operations toemploy highly maneuverable hoisting vehicles, commonly referred to aslift trucks for the purpose of loading and unloading cartons ofmerchandise from the cargo carriers and for stacking the merchandise inthe warehouse. These lift trucks are conventionally provided with two ormore forwardly projecting fingers which are adapted to be moved beneatha stack of cartons for hoisting the stack and moving it from onelocation to another.

In the past, it has been necessary to provide pallets of rigidconstruction for supporting the stack of cartons in spaced relationshipfrom a supporting surface, such as the floor of a rail car, the floor ofthe warehouse, or the top of other stacks of merchandise. These pallets,usually constructed of wood, have been necessary to permit insertion ofconventional forklift fingers beneath the stack and also to maintain theintegrity of the stack on the fingers when the stack is hoisted by thelift ruck.

These wooden pallets, although heretofore thought essential to mostwarehousing operations, increase the cost of the operation by virtue ofthe costs of manufacturing the pallets themselves, storage andtransportation space occupied by the pellets, and the sheer nuisance andlabor expense involved in handling and collecting the individual palletsin the warehouse after the stacks of merchandise have been removedtherefrom.

As an alternative to the use of 'wooden pallets in the shipping ofmerchandise, it has heretofore been necessary for each individual cartonto be manually loaded onto a pallet or platform supported by the lifttruck before the goods can be transported to the desired location. Thetime consumed and the labor expenses involved in such manual loadingoperations usually outweigh the expense which is involved in the use ofWooden pallets throughout.

The principal object of this invention, therefore, is to provide anextension or attachment for use with conventional lift trucks so thatthe latter are capable of handling stacks of merchandise in cartonswithout need for the cartons to be stacked upon pallets.

Another object of the invention is to provide novel finger extensionswhich are capable of each and rapid installation or removal fromconventional fork-lift trucks so that the latter may be utilized forhandling both palletized and non-palletized shipments of merchandise.

A further object of the instant invention is to provide fingerextensions constructed to permit rapid pickup of 3,353,697 Patented Nov.21, 1967 non-palletized stacks of cartons through maneuver of the lifttruck by the operator and without need for auxiliary workmen to assistin either loading or unloading the vehicle.

Still another object of this invention is to provide novel fingerextensions as hereinabove set forth, yet which may be quickly andeconomically manufactured from commercially available materials.

These and additional objects of this invention will be further explainedor will become apparent from the following specification and claims.

In the drawings:

FIGURE 1 is a perspective view on a reduced scale of a fork-liftequipped with the novel finger extensions of this invention and shownsupporting a unitized stack of cartons;

FIG. 2 is a fragmentary, front elevational view of the lifting rack of alift truck with the finger extensions mounted on the fingers, cartons ofa stack of merchandise supported by the finger extensions appearing indot and dash lines;

FIG. 3 is a horizontal, cross-sectional view through the rack, revealinga top plan view of the finger extensions;

FIG. 4 is a bottom plan view of a finger extension embodying theprinciples of this invention;

FIG. 5 is a side elevational view of the fork-lift rack and fingerextensions of FIG. 3, a portion of the load appearing in dot and dashlines;

FIG. 6 is a cross-sectional view taken along irregular line 6--6 of FIG.4; and

FIG. 7 is a view similar to FIG. 3 but With a third fork-lift finger andfinger extension appearing in place on the rack.

Referring initially to FIGURE 1, a lift truck numerated 10 of Well-knownconstruction is provided with a pair of finger extensions 12 and 13embodying the principles of the instant invention for hoisting aunitized stack 14 of cartons 16 containing merchandise or the like.Truck 10 is provided in conventional manner with an upright trackbroadly denoted by the numeral 18. Truck 1-8 includes a movable rack 20(FIG. 2) which is operably coupled with hoisting apparatus carried bytruck '10 as is conventional, and rack 20 is shiftable along track 18over an upright, reciprocable path of travel by the hoisting apparatuswhich is under the direct control of the operator of truck 10.

Rack 20 is provided with a pair of outermost, upright members 22 whichare interconnected at vertically spaced intervals by an uppermost crossmember 24, and a lower cross member 26. Upper member 24 has a pluralityof longitudinally spaced notches 28 in the upper marginal edge thereof.Notches 28 cooperate with projecting structure (not shown) on theupright portions 30 and 32 of generally L-shaped teeth or fingers 34 and36 respectively, for securing the fingers to rack 20 as illustrated inFIG. 2.

Each of the fingers includes integral, forwardly extending, generallyhorizontally disposed finger portions numerated 38 and 40 respectively.Portions 38 and 40' project forwardly from rack 20 and areconventionally utilized for lifting loads along the reciprocable path oftravel of track 18 after portions 38 and 40 have been inserted beneaththe load. Manifestly, each of the fingers 34 and 36 are movablelaterally along the members 24 and 26 to provide any selected horizontalspacing between the respective fingers.

When loads are lifted by use of fingers 38 and 40, it has, in the past,been necessary to provide vertical spacing between the load and asupporting surface such as a floor or the like to permit insertion ofthe fingers beneath the load. Also, it has been common practice toutilize a rigid platform beneath the load and above the fingers it whenloads comprised of a plurality of units such as cartons, are handled.Such vertical spacing and rigid platform is commonly provided by thewooden pallets mentioned above.

The finger extensions 12 and 13 capable of eliminating the necessity forsuch pallets comprise elongated, rigid, generally flat plates 42 havingupper surfaces 44 and lower surfaces 46. It may be seen, particularly inFIG. 2, that extension 12 is similar to extension 13 with the exceptionthat the supporting structure on the lower surface 46 of extension 13 issubstantially a mirror image of the corresponding structure .onextension 12. Thus, it is only necessary to describe the details ofconstruction of extension 12 to explain the principles of the instantinvention.

Plate 42 is substantially longer than the horizontal portions 38 and 40of fingers 34 and 36, and the outwardly extending end of plate 42projects beyond the outermost tip of the corresponding fingers. Theupper surface 44 of each of the plates 42 is beveled downwardly asillustrated in FIGS. 3 and 6, with the extent of bevel increasing as theoutermost end of the finger extension is approached.

An elogated strap member 48, having opposed ends thereof rigidly securedto plate 42, projects outwardly beyond the other end of the latter todefine a loop extending in spaced relationship from said other end ofeach plate 42. The upright portions 36 and 32 of fingers 34 and 36respectively, are received between the loop formed by member 48 and theproximal end of plate 42 as shown best in FIG. 3.

Elongated, downwardly extending flanges 50 and 52 integral with thebottom surface 46 of each plate 42 extend longitudinally of the latterat each marginal edge of plate 42. The outermost portions of flanges 50and 52 are tapered upwardly as the outermost ends thereof areapproached, as clearly shown in FIGS. and 6. A medial flange 54 extendsfrom the bight portion of member 48 in parallel relationship to flange50 and in spaced relationship from flange 52 as shown best in FIG. 4.

A series of parallel cross bracing flanges 56 are welded to flanges 52and 54 respectively, and extend therebetween for providing structuralrigidity to flange 54. The spacing between the flanges 50 and 54 ischosen to accommodate therebetween the elongated, generally horizontallyextending finger portion 38 or 40 when the finger extension is mountedon the corresponding finger. It should be noted at this juncture thatthe spacing between flanges 50 and 54 is not centrally located withrespect to the corresponding extension 13. Accordingly, plate 42, whichis substantially wider than the finger of the lift truck, projectsoutwardly beyond the outermost edge of the corresponding lift truckfinger when the extensions are in place as clearly illustrated in FIG.2. Therefore, with the fingers adjusted to the positions thereof ofmaximum horizontal spacing therebetween, as shown in FIG. 2, the fingerextensions 12 and 13 extend a substantial distance horizontallyoutwardly beyond the fingers.

It may be desired for some lifting operations that a third finger 58 beutilized in conjunction with the outer fingers 34 and 36. Thus, a middlefinger extension broadly designated 60 may be provided for the middlefinger 58 a shown in FIG. 7. Manifestly, extension 60 is ordinarilydisposed midway between extensions 12 and 13 in the manner illustrated.It should be noted that the middle extension 60 is provided with a pairof flanges 54 Welded to the lowermost surface of plate 42. The flanges54 are spaced apart a suflicient distance to accommodate thehorizontally extending portion of the finger 58 therebetween when theextension 60 is in place on the finger. In the case of the middleextension 60, the latter projects on either side of finger 58 an equaldistance.

In operation, the cartons 16 to be handled by equipment utilizing theprinciples of this invention, are stacked in what is commonly referredto as a unitized load. Such a load is illustrated in FIG. 1. The stackis generally prismatic (and may or may not be cubical) with the cartonsstacked in layers substantially oriented in the manner illustrated inFIG. 1.

Each layer includes two adjacent rows 63, of three cartons disposed inend to end relationship, and two groups 64 of two cartons each. Thegroups 64 comprise a pair of side-by-side cartons 16, the longitudinalaxis of the cartons of the groups extending at right angles from thelongitudinal axis of the cartons of the rows 63 of the same layer. Theends of the cartons of each group 64 abut the side of a proximal cartonof a row 63. The cartons of the groups 64 and the rows 63 of one layeroverlie the cartons of the rows 63 and groups 64 respectively of thenext lowermost layer.

It should be noted that each carton has a longer length dimension thanthe width dimension thereof. When the extensions 12 and 13 are installedon truck 10 in the manner illustrated in FIG. 2, the outermost edges ofthe extensions are located along imaginary lines extending from front torear along the stack and disposed at least as close as one-half of thelength dimension of one carton from the outermost edges of the stack.This insures that the extensions underlie the centers of gravity of theoutermost cartons of each row 63 and prevent the stack from tending tosplit or the cartons toppling outwardly when the load is lifted by thetruck. On the contrary, the finger extensions are thereby disposed withrespect to the structural make-up of the stack to insure integrity ofthe stack during transportation of the load. It has been found that eachsucceeding layer above the bottom layer of cartons is bound tightly bygravity to the lowermost layer as the stack is lifted when theextensions are in place as illustrated.

In utilizing the extensions of this invention, the shippers stack theunitized load on a relatively thin membrane or sheet 62, shown best inFIG. 5. The sheet 62 is ordinarily of cardboard, fiberboard or othersemiflexible material. The outwardly projecting and downwardly beveled,outermost portions of the finger extensions permit the operator of truck10 to insert the extensions beneath sheet 62 by manipulation of thetruck. This may be accomplished even though the sheet 62 rests on afloor or other supporting surface and it is not necessary when thefinger extensions are utilized to provide vertical spacing between thebottom of the stack and the supporting surface.

The presence of the semi-flexible sheet or member 62 beneath the stackprevents the middle of the latter from capsizing when the stack islifted. Thus, referring to FIG. 1, the middle carton 16a is held insupported position between the finger extensions inasmuch as member 62is bound tightly by friction between the upper surfaces of theextensions and the adjacent cartons 16. Manifestly, the other cartons ofthe lowermost layer of the stack which are not directly supported by therelatively broad, long surfaces of the finger extensions are similarlysupported by the member 62. However, when a central extension 60 isutilized, all of the cartons of the lowermost layer of the stack restdirectly upon finger extensions.

The flanges on the lowermost surfaces 46 of plates 42 serve to stabilizethe extensions in place on the corresponding fingers. However, when itis desired to remove the finger extensions so that the fingers of thefork-lift truck can be used with conventional palletized loads, it isonly necessary that the outermost end of the extension be tippedupwardly. This frees the member 48 from engagement around the uprightportion of the finger, whereupon the extension may be removed from thefinger. Conversely, the extensions can be quickly and easily installedon the finger by inserting the latter through the loop formed by member48 and sliding the extension on the rear of the finger so that theupright portion of the finger is received between the member and theproximal end of the plate 42.

The use of the finger extensions of this invention is somewhat enhancedif the upper surfaces 44 thereof are maintained in smooth condition. Thesurfaces may be polished and coated with wax or the like to permit readyinsertion of the extensions beneath the flexible member upon which theload is stacked. Furthermore, these slick surfaces allow the load todisengage readily from the finger extensions when it is desired toremove the lift truck from the load. This is easily accomplished by theoperator, particularly if he manipulates the load so that theforwardmost edge thereof comes into contact with the supporting surfaceupon which he desires to deposit the load and the truck is thenmaneuvered away from the load while the latter is tipped slightlyforwardly at a small angle.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. For use with an article-lifting apparatus having a mobile hoistprovided with an L-shaped finger having an upright portion and agenerally horizontally extending terminal portion shiftable through agenerally upright, reciprocable path of travel, a finger extensioncomprising:

an elongated, rigid plate of greater length and width than said terminalportion of the finger;

an elongated strap member having opposed ends thereof secured to theplate adjacent one end of the latter, said member defining a loopadjacent said one end of the plate, the upright portion of the fingerbeing received through said loop with the plate supported by saidterminal portion of the finger disposed thereunder, the upper surface ofsaid plate being provided with a downwardly extending bevel having arounded, convex edge adjacent the other end of said plate; and

means on the plate engageable with the terminal portion of the fingerfor releasably holding the plate on the finger, said holding meansincluding a pair of spaced, elongated, downwardly projecting flanges onsaid plate, said flanges extending longitudinally of the plate anddisposed to oppositely engage the terminal portion of said finger, oneof said flanges extending from the bight of said loop forwardly inparallelism with said other flange, a third flange extending in parallelrelationship to said pair of flanges, and brace members secured to saidplate and interconnecting said one flange with said third flange, saidflanges tapering upwardly as the forwardmost ends thereof areapproached.

2. #In merchandising lifting and transporting apparatus, the combinationof:

a mobile hoist having a pair of elevatable, spaced, L- shaped, liftingfingers each including an upright portion and a generally horizontallyextending terminal portion;

a sheet of semi-flexible material;

a unitized load upon said sheet and formed of a plurality of individualcartons in stacked relationship; and

a finger extension for each of said fingers respectively, each of saidextensions including an elongated, rigid plate of greater length andwidth than said terminal portion of the corresponding finger supportedon top of the latter, means including an elongated strap member havingopposed ends secured at one end of each plate and looped around saidupright portion for releasably securing the same to said upright portionof the corresponding finger, and means on each plate engageable withsaid terminal portion of the corresponding finger for releasably holdingsaid plate thereon, said holding means including a pair of downwardlyextending flanges disposed at opposite marginal edges of said plate, amedial flange extending from the strap member forwardly in spacedparallelism with one of the pair of flanges to receive a correspondinglifting finger therebetween, and rigid brace means interconnecting saidmedial flange and said one flange, said flanges tapering upwardly as theforwardmost ends thereof are approached, each plate terminating in athin, downwardly extending bevelled section having a rounded, convexedge to facilitate insertion of said extension under said sheet, theoutermost edges of said extensions being spaced apart a distancesuflicient for said extension to underlie at least a portion of theoutermost lower cartons at a pair of opposite extremities of said stack.

References Cited UNITED STATES PATENTS 2,610,751 9/1952 Bevan 2146212,788,909 4/1957 Kughler 214620 2,808,157 10/ 1957 Terrill 214382,913,206 11/1959 Paris 108-51 2,955,721 10/1960 Hepler et al. 2l45143,283,933 11/1966 Vander Wal 214O FOREIGN PATENTS 564,185 10/1958Canada.

GERALD M. FORLENZA, Primary Examiner.

IR. B. JOHNSON, Assistant Examiner.

1. FOR USE WITH A ARTICLE-LIFTING APPARATUS HAVING A MOBILE HOISTPROVIDED WITH AN L-SHAPED FINGER HAVING AN UPRIGHT PORTION AND AGENERALLY HORIZONTALLY EXTENDING TERMINAL PORTION SHIFTABLE THROUGH AGENERALLY UPRIGHT, RECIPROCABLE PATH OF TRAVEL, A FINGER EXTENSIONCOMPRISING: AN ELONGATED, RIGID PLATE OF GREATER LENGTH AND WIDTH THANSAID TERMINAL PORTION OF THE FINGER; AN ELONGATED STRAP MEMBER HAVINGOPPOSED ENDS THEREOF SECURED TO THE PLATE ADJACENT ONE END OF THELATTER, SAID MEMBER DEFINING A LOOP ADJACENT SAID ONE END OF THE PLATE,THE UPRIGHT PORTION OF THE FINGER BEING RECEIVED THROUGH SAID LOOP WITHTHE PLATE SUPPORTED BY SAID TERMINAL PORTION OF THE FINGER DISPOSEDTHEREUNDER, THE UPPER SURFACE OF SAID PLATE BEING PROVIDED WITH ADOWNWARDLY EXTENDING BEVEL HAVING A ROUNDED, CONVEX EDGE ADJACENT THEOTHER END OF SAID PLATE; AND MEANS ON THE PLATE ENGAGEABLE WITH THETERMINAL PORTION OF THE FINGER FOR RELEASABLY HOLDING THE PLATE ON THEFINGER, SAID HOLDING MEANS INCLUDING A PAIR OF SPACED, ELONGATED,DOWNWARDLY PROJECTING FLANGES ON SAID PLATE, SAID FLANGES EXTENDINGLONGITUDINALLY OF THE PLATE AND DISPOSED TO OPPOSITELY ENGAGE THETERMINAL PORTION OF SAID FINGER, ONE OF SAID FLANGES EXTENDING FROM THEBIGHT OF SAID LOOP FORWARDLY IN PARALLELISM WITH SAID OTHER FLANGE, ATHIRD FLANGE EXTENDING IN PARALLEL RELATIONSHIP TO SAID PAIR OF FLANGES,AND BRACE MEMBERS SECURED TO SAID PLATE AND INTERCONNECTING SAID ONEFLANGE WITH SAID THIRD FLANGE, SAID FLANGES TAPERING UPWARDLY AS THEFORWARDMOST ENDS THEREOF ARE APPROACHED.